1. Field of the Invention
This invention relates to a metallic-tone lacquer composition for tinting a metal substrate. More particularly, the invention relates to a sprayable film-forming composition exhibiting a metallic appearance for forming a protective and decorative film on a metal surface.
2. Description of the Prior Art
The original luster and shine of metal surfaces are often lost upon extended exposure to environmental conditions. After prolonged periods of environmental exposure, surfaces of metal articles and constructions which are intended to present an ornamental appearance eventually deteriorate and become decidedly unsightly. In many instances refinishing or restoration of these deteriorated surfaces is necessary, since the replacement costs involved would be economically prohibitive. However, commercial refinishing processes which permit dipping the entire metal surface to be restored into an electrocoating bath or coating composition and then prompt drying of the coated surface are costly and time-consuming operations. Of course, it is not always feasible to have access to a commercial facility and merely repainting the damaged area by spraying the paint onto the metal surface does not result in a finish that approaches the original metallic appearance.
Efforts to improve the metallic appearance of surfaces have also included the use of improved lacquer compositions and presently for best results multicoat systems are used for refinishing. Multicoat coating systems comprising a metallic pigmented base coat and at least one clear resinous top coat are well known is the art as described in U.S. Pat. No. 3,639,147 to Benefiel et al. and more recently in U.S. Pat. No. 4,753,829 to Panush. However, the base and top coat compositions of the prior art are typically applied separately to a substrate by sophisticated spraying methods such as compressed air spraying, electrostatic spraying, hot spraying techniques, etc., performed using specially designed automated equipment usually only available in manufacturing facilities. Moreover, it is generally accepted that the preparation and application of these coating systems requires a high degree of skill and experience to obtain the desired metallic brilliancy and tone.
Among the host of commercially available lacquers, few may be utilized to tint a metal substrate and none appear suitable for application from readily available dispensers such as aerosol containers. This is due to the fact that most metal tinting lacquer compositions undergo severe discoloration under the influence of environmental exposure and the film coatings themselves are subject to cracking, followed by peeling and blistering. Another problem encountered in spray coating of a metal surface is an uneven, wrinkled surface that results when the film dries too quickly and entraps solvents beneath the surface of the film. Also, an uneven appearance may result when using metallic paints and drying is not carried out properly. The metallic particles, instead of being substantially uniformly distributed throughout the lacquer, tend to clump together and give a spotted appearance.
Accordingly, those skilled in the art will appreciate that it would be highly desirable to provide a conveniently sprayable metallic-tone lacquer composition for tinting a metal substrate which overcomes the problems discussed above.